The motor system is responsible for impulses originating from the central nervous system and reaching the body.
Two subdivisions:
Somatic Nervous System: Innervates skeletal muscles.
Autonomic Nervous System: Innervates smooth and cardiac muscles, typically under involuntary control.
Regulators of skeletal muscle function.
Important for voluntary movements and related to the next topic of skeletal muscles.
Impulses originate from the brain, influencing muscle movement.
Cerebellum: Integrates sensory information related to equilibrium, balance, and proprioception.
Sensory Receptors:
Muscle Spindles: Located within skeletal muscles, providing feedback on muscle length and rate of change.
Golgi Tendon Organs: Embedded in tendons, providing information on muscle tension.
Lower Motor Neurons:
Located in the ventral horn of the spinal cord or brainstem.
Travel to skeletal muscles through the ventral root of spinal nerves.
Function as a final common pathway (one neuron to one muscle).
Influenced by sensory feedback, which may have facilitatory or inhibitory effects.
Lower Motor Neurons:
Located in the brainstem/spinal cord.
Directly responsible for muscle contraction.
Evidence of commissural and ipsilateral tracts.
Upper Motor Neurons:
Input to lower motor neurons, playing key roles in voluntary movements.
Examples include direct and indirect motor pathways from the brain.
Basal Ganglia System:
Regulates initiation and control of motor responses based on sensory input and feedback.
Plays a significant role in forming correct motor responses.
Degeneration Example: Huntington's disease demonstrates how basal nuclei degeneration affects movement control.
Acts like a ‘tattle tale’ to the primary motor cortex by comparing intended movements with actual movements.
Functions under high complexity due to continuous sensory input and motor command integration.
Direct Motor Pathways:
Deliver signals from the cerebral cortex to lower motor neurons, controlling voluntary movements.
Indirect Motor Pathways:
Involved in reflexes and posture control.
Corticospinal Pathways: Includes lateral and anterior corticospinal tracts.
Hyperdirect Pathway: Rapidly influences motor control independently of voluntary processes.
Comprised of structures like the caudate nucleus, putamen, and globus pallidus, crucial for motor control.
Involvement in voluntary movement selection and abnormal movement patterns in disorders like Huntington's disease.
Coordinates voluntary muscle movements by processing incoming sensory information from various sources (muscles, joints, ears, eyes).
Sends corrective signals to the motor cortex rather than directly influencing muscle contractions.
Cerebellar pathways receive input from different sources to ensure precise motor output.
Highlights the distinction between actual movements and intended movements via corrections sent to the primary motor cortex.
The motor system encompasses a complex interaction between the central nervous system and muscles, with specific pathways and structures playing pivotal roles in coordinating voluntary and involuntary muscle movements.
Recording-2025-02-13T17_46_16.965Z
The motor system is responsible for impulses originating from the central nervous system and reaching the body.
Two subdivisions:
Somatic Nervous System: Innervates skeletal muscles.
Autonomic Nervous System: Innervates smooth and cardiac muscles, typically under involuntary control.
Regulators of skeletal muscle function.
Important for voluntary movements and related to the next topic of skeletal muscles.
Impulses originate from the brain, influencing muscle movement.
Cerebellum: Integrates sensory information related to equilibrium, balance, and proprioception.
Sensory Receptors:
Muscle Spindles: Located within skeletal muscles, providing feedback on muscle length and rate of change.
Golgi Tendon Organs: Embedded in tendons, providing information on muscle tension.
Lower Motor Neurons:
Located in the ventral horn of the spinal cord or brainstem.
Travel to skeletal muscles through the ventral root of spinal nerves.
Function as a final common pathway (one neuron to one muscle).
Influenced by sensory feedback, which may have facilitatory or inhibitory effects.
Lower Motor Neurons:
Located in the brainstem/spinal cord.
Directly responsible for muscle contraction.
Evidence of commissural and ipsilateral tracts.
Upper Motor Neurons:
Input to lower motor neurons, playing key roles in voluntary movements.
Examples include direct and indirect motor pathways from the brain.
Basal Ganglia System:
Regulates initiation and control of motor responses based on sensory input and feedback.
Plays a significant role in forming correct motor responses.
Degeneration Example: Huntington's disease demonstrates how basal nuclei degeneration affects movement control.
Acts like a ‘tattle tale’ to the primary motor cortex by comparing intended movements with actual movements.
Functions under high complexity due to continuous sensory input and motor command integration.
Direct Motor Pathways:
Deliver signals from the cerebral cortex to lower motor neurons, controlling voluntary movements.
Indirect Motor Pathways:
Involved in reflexes and posture control.
Corticospinal Pathways: Includes lateral and anterior corticospinal tracts.
Hyperdirect Pathway: Rapidly influences motor control independently of voluntary processes.
Comprised of structures like the caudate nucleus, putamen, and globus pallidus, crucial for motor control.
Involvement in voluntary movement selection and abnormal movement patterns in disorders like Huntington's disease.
Coordinates voluntary muscle movements by processing incoming sensory information from various sources (muscles, joints, ears, eyes).
Sends corrective signals to the motor cortex rather than directly influencing muscle contractions.
Cerebellar pathways receive input from different sources to ensure precise motor output.
Highlights the distinction between actual movements and intended movements via corrections sent to the primary motor cortex.
The motor system encompasses a complex interaction between the central nervous system and muscles, with specific pathways and structures playing pivotal roles in coordinating voluntary and involuntary muscle movements.